Compositions containing boron have long been used in the field of pest control, particularly in insecticides. More recently, boron compounds have declined in use due to the availability of modern synthetic insecticides. However, there are several drawbacks associated with synthetic insecticides, including resistance development in the pests, re-registration costs, and safety concerns by homeowners. These problems have renewed interest in boron compounds for use in pest control.
Historically, the use of boron compounds in structural pest control has been directed at cockroaches. More recently, research and development has been aimed at the use of boron compounds (e.g., boric acid) in the control of ants, cockroaches, fleas, and wood-destroying organisms.
Among the pests most sought to be controlled are ants, cockroaches and fleas. With ants, if a bait is sufficiently attractive it will be rapidly carried back to the ant nest and distributed to the entire ant colony. To effectively kill the ant colony, a slow-acting toxicant is required so that the ants have sufficient time to collect and distribute the insecticide before it reaches a lethal level.
In low concentrations, boric acid acts as a slow-acting toxicant. One advantage to using boric acid to kill ants is its solubility in water. Not only is water a convenient carrier, but it also helps meet the ants' need for moisture in their diet. Additionally, liquid baits exploit the natural feeding habits of sweet-eating ants that collect honeydew, nectar and other plant juices. Another advantage of using boric acid to kill ants is that it acts like a desiccant (i.e., a substance that removes moisture), causing dehydration of the ants, which causes them to consume more of the liquid bait.
With respect to control of cockroaches, boric acid has been used primarily as a stomach poison, either as a dust that is ingested by the cockroach during grooming, or as a toxicant incorporated into a bait. Only secondarily does the boric acid kill by contact. Traditionally, the concentration of boric acid used in cockroach bait has been very high. In some cases, the bait may consist of 50% or more boric acid.
Boric acid is also useful in the control of fleas. In this regard, it has been found that boric acid effectively controls fleas when applied to the actively feeding larval stages of the fleas. Killing of the larvae breaks the life cycle of the fleas, and leads to eventual control of the flea population. The boric acid is believed to kill through ingestion since boric acid appears to lack contact toxicity in fleas.
Among the problems encountered with the use of borates (e.g., boric acid or triethyl borate) as a pest-controlling composition is that borates are relatively slow acting and lack potency. Accordingly, prior art pest-controlling compositions use high concentrations of borates. However, the use of increased borate concentrations has numerous drawbacks. In this regard, there is a potential for bait avoidance by the pests. For instance, fire ants are known to avoid ant baits having a borate content of 1% or more. Furthermore, high borate concentrations also pose a hazard to the environment. In this respect, borates are toxic or injurious to plants (i.e., phytotoxic). Moreover, the increased borate concentrations may also threaten customer safety. The prior art fails to provide a pest-controlling composition using borate compounds in low concentrations, and which also provides quick and effective pest control.
The present invention overcomes these and other drawbacks of using borate compounds in a pest-controlling composition.